Research on the Expansion Characteristics and Compressive Strength of Mortars Containing Circulating Fluidized Bed Combustion Desulfurization Slag

Zhi Cheng,Hua Hou,Zhijun Cheng,Lan Liu,Tao Han

doi:10.1155/2018/4150145

Zhi Cheng, Hua Hou + Show 3 more

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https://doi.org/10.1155/2018/4150145

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Abstract

Circulating fluidized bed combustion (CFBC) desulfurization slag is a waste residue discharged from coal power plants. In this article, expansion characteristics and compressive strength of mortars containing CFBC desulfurization slag were evaluated, subjected to mechanical grinding time, the amount of additive, and chemical activation. Correlations between the linear expansion rate and compressive strength were investigated. The hydration products of cement-slag cementitious system were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that mechanical grinding can increase both the expansion and compressive strength of mortars containing CFBC desulfurization slag, and the compressive strength and linear expansion can develop in coordination. While increasing the amount of the fine desulfurization slag, the linear expansion rate increases, and the compressive strength reaches to the maximum when the amount is 30%. Moderate sodium sulfate as an activator can both promote the compressive strength and increase the expansion of mortars.

Highlights

In 2012, coal accounted for about 30% of primary energy sources available and played a role in 41% of the world’s electricity generation
Samples were labeled as T1, T2, T3, T4, and T5 and used in this experiment. e physical and chemical properties of Circulating fluidized bed combustion (CFBC) desulfurization slag were determined by an ARL 9800XP plus X-ray uorescence (XRD), and the results are given in Table 1 and Figure 1
We can conclude that the linear expansion rate is positively correlated with the compressive strength under di erent grinding times

Summary

Introduction

In 2012, coal accounted for about 30% of primary energy sources available and played a role in 41% of the world’s electricity generation. As the largest country in terms of coal consumption in the world, China consumed 2.943 billion tons of standard coal equivalent in 2013, accounting for more than half of the global total. It is estimated that global coal consumption will increase by more than 50%, as compared with 97% in developing countries, by 2030 [1, 2]. Because limestone is added to CFBC as a desulfurizer, the discharged ash and slag of CFBC are 30%–40% more than those of pulverized coal combustion. E comprehensive utilization of CFBC ash and slag has aroused much attention Most of them cannot be utilized and stacked directly in storage sites, which occupied the land and polluted the environment and wasted. e comprehensive utilization of CFBC ash and slag has aroused much attention

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Conclusion